Because of the limited availability of resources, conservation of power, gas and water has become increasingly important and valuable to both consumers and public utility companies. Production costs for all utilities have escalated as it becomes increasingly expensive to build and operate utility plants. The increasing scarcity of these resources and increasing consumption makes it increasingly difficult for utility companies to supply all the utilities to all their customers at all times. Residential consumers see their utility expenditures growing as utility rates and usage escalate. Consumers and utility companies recognize the need to monitor and conserve electrical energy.
For example, the need has been recognized for residential consumers to utilize their electric power meters in monitoring their usage of electrical power. This need has been recognized because residential power users receive a monthly or bi-monthly bill documenting how much energy they have used. However, by the time the bill arrives, the opportunity to alter electrical power consumption has been missed. Consequently, there is a need for real-time information about electrical power consumption in order to make real-time usage adjustments.
Residential electrical energy usage is typically monitored by power companies through an electrical meter mounted external to the residential building. In most cases, these meters are connected to receive a three-line 240 VAC power feeder that includes a neutral wire and two 120 VAC power lines. The meter includes a transparent case having a horizontal disk mounted on a vertical shaft inside. The vertical shaft and disk rotate in response to the flow of electric current from the public utility lines through the meter to the residential house wiring. The horizontal disk includes one or more index marks near the periphery of the flat sides of the disk. The index mark is used by the public utility agency for calibrating the meter at the time of installation.
While several methods have been proposed for monitoring residential power consumption, these methods suffer from a number of disadvantages. For instance, U.S. Pat. No. 4,630,211, issued to Pettis on Dec. 16, 1986, teaches a watt-hour meter display for informing consumers of energy consumption. As taught by Pettis, an infrared sensor is mounted on the electric meter inside the transparent cover to monitor rotation of the horizontal disk. A portable display unit is provided on the interior of the house that communicates with the infrared sensor by means of the residential house wiring. The major drawback to this method is that the electric power meter must be partially dismantled and altered to enable installation of the infrared sensor. Power companies are unwilling to invest the time and man power in installing these devices and they are unwilling to permit consumers to dismantle the meter and install the devices themselves. Consequently, the consumer must pay a large fee to have the device installed in the meter. Another disadvantage of this and other methods is the inability of these prior art devices to coordinate the monitoring and display of electrical power consumption data with the billing cycle of the power company. In other words, the consumer has no idea of knowing when the meter has been read to enable them to compare power consumption data provided by the public utility company with the data generated by these prior art methods. Consequently, the usefulness of information provided by this and similar prior art methods is limited.
As is evident, there is a need for a power consumption monitoring device that can be easily installed by a consumer without requiring permission of the power company or tampering of the electric meter and/or the house and building wiring. Furthermore, there is also a need for such a device to be coordinated with the power company's billing cycle to enable accurate comparison and verification of usage. It will be recognized that this need extends to gas and water meters as well.